Zoology - Principles of Inheritance and Variation Question with Solution | TestHub

Colour blindness is a X-linked recessive disorder. In it, the affected individual has is not able to distinguish colour especially read and green. X-lined disorders are inherent disorders due to mutation in the X-chromosome which causes the phenotype to be always expressed in male and in female only in homozygous condition. The daughter will receive one X chromosome from father (the chromosome with colour blindness gene) and other X (normal chromosome) from mother. Therefore, all daughters born will be carriers.

The son will receive Y chromosome from father and a X chromosome from mother. Thus, all sons will be normal.